X-bay tube



F J. FARRELLY AND A. GREINER. X-RAY TUBE.

APPLICATION FILED 06127.19]?- 1,334, 146. Patented Mar. 16', 1920.

IN VENTOR. Exam-is cl i'arr'ell z A Z fred fireinel:

BY [if/# @L ATTORNEY.

UNITED srATEs PATENT onnion.

FRANCIS J". FARRELLY AND ALFRED GREINER, OF HARTFORD, CONNECTICUT.

X-RAY TUBE.

Specification of Letters Patent.

Patented Mar. 16, 1920.

Application filed October 27, 1917. Serial No. 198,793.

To all whom it may concern:

Be it known that we, FRANCIS J. FARRELLY and ALFRED GREINER, citizens of the United States, and residents of Hartford, county of instance it is now customary, and by some considered necessary, to use a rectifying switch in connection with a transformer for exciting X-ray tubes. It has been found that the new tube will operate perfectly with such a transformer without using the rectifying switch. Again, certain exciting apparatus has been constructed which has no rectifying switch, other means being utilized for cutting out the inverse current. It has been found that where the ordinary tube will not operate successfully when excited from such a machine, the new tube will operate perfectly under the same conditions and has a capacity for taking on very much heavier current. So far as now appears it seems that the new tube will operate satisfactorily with any transformer producing high tension current for the exciting of X-ray tubes. It is believed that the current consumption of the new tube will be less than is common with other tubes and that the new tube will have a greater penetration and quicker action.

From observing the actions of X-ray tubes it appears that certain electrical manifestations, such perhaps as static fields, are set up on the outside of the tube and are particularly noticeable at the point opposite the cathode. The presence of the exterior circuit between the positive and negative ends of the tube, as provided by this invention, seems to provide an agency for neutralizing these fields and to avoid danger f breakage of the bulb at the cathode.

An embodiment of the invention is illustrated in the drawing which isa sideview of an X-ray tube equipped with the improvement. Referring to the drawing, a denotes the ordinary bulb; b the anode shank, 0 the cathode shank; d the anode; e the cathode; f the bi-anode and g the regulator.

The cathode end of the tubeis the nega tive end, and the anode end the positive end' 10 denotes tinfoil or similar material applied to the anode neck at a proper point intermediate its end and beyond sparking distance from the tube terminal. 5, denotes a similar tinfoil applied to the cathode neck and preferably opposite the cathode. Embedded in the foil at each end of the tube are conductors, as the wires 11, 16, connected by the wire 17. The tubular glass posts 20, fused to the necks position the foil and provide a convenient support for the wires. Other means for establishing the desired electrical connection between the necks are known to be applicable and it is not our wish to be limited to the precise embodiment shown, which is merely illustrative of one way of carrying out the invention.

Vi e claim as our invention 1. The combination with an X-ray tube and its ordinary energizing circuit of a path of electrical conduction arranged between the exteriors of the positive and negative ends of said tube.

2. The combination with an X-ray tube of conducting material applied to the exterior of the negative end of said tube at a point approximately opposite the cathode, a second piece of conducting material applied to the exterior of the positive end of the tube at a distance from the tube terminal, and a path of electrical conduction connecting said pieces of conducting material exteriorly of said tube.

3. The combination with an X-ray tube of a tubular post fused tothe exterior of the cathode neck of said tube adjacent to the cathode, conducting material located in the bottom of said tube against theexterior wall of the cathode neck, a similar tube fused to the exterior wall of the anode neck at a substantial distance from the tube terminal, conducting material positioned in the bottom of said tube against the Wall of the.

anode neck, conducting Wires having an end embedded in the conducting material the outer ends of said posts providing a support for said Wires, and an electrical conductorl connecting the iireeends of said Wires.

4. The combination With an X-ray tube and its ordinary energizing circuit of means for neutralizing the electrical manifestw 10 tions at the positive and negative ends of said tube.

v J IGIS J.- ABRELL ALFRED GREINER. 

